Adjustable underside tension lockup means



March 1, 1966 E. w. woRrHlNGToN ETAL 3,237,557

ADJUSTABLE UNDERSIDE TENSION LOOKUP MEANS 4 Sheets-Sheet 1 Filed Sept. 18 1963 INVENTORS EMORY W. WORTHINGTON BYWILLIAM J. GRAZINE March 1, 1966 E. w. woRTHlNGToN ETAI. 3,237,557

ADJUSTABLE UNDERSIDE TENSION LOCKUP MEANS Filed Sept. 18 1963 4 Sheets-Sheet 2 INVENTORS EMORY W. WORTHING TON BYwuLLmM .1.GRAzlNE -g iwf/nm, /74 JAN ATTORNEYS March 1,'1966 Filed sept. .18, 196s E. W. WORTHINGTON ETAL ADJUSTABLE UNDERSIDE TENSION LOCKUP MEANS 4 shets-sheet s FIG. 6

FIG. 5

' INVENTORS I EMORY W. WORTHINGTON YWILLIAM J.GRAZINE ATTORNEYS March 1, 1966 Filed Sept. 18, 1963 FIG. 7

E. W. WORTHINGTON ETAL ADJUSTABLE UNDERSIDE TENSION LOCKUP MEANS 4 Sheets-Shea?l 4 INVENTORS EMoRY w. woRTHlNGToN BYWILLIAM .I GRAzlNE 45AM Mami-3A w ATTORNEYS United States Patent O 3,237,557 ADJUSTABLE UNDERSIDE TENSION LOCKUP MEANS Emory W. Worthington, Ridgewood, and William J. Grazine, New Brunswick, NJ., assignors to Wood Newspaper Machinery Corporation, Plainfield, NJ., a corporation of Virginia Filed Sept. 18, 1963, Ser. No. 309,688 2 Claims. (Cl. 101-378) This invention relates to apparatus for the underside locking of stereotype printing plates onto printing cylinders and, more particularly, to apparatus whereby the positioning of a plate on a printing cylinder may be accurately regulated and maintained.

Underside tension lockup apparatus involves means whereby heavy stereotype printing plates may be securely held onto printing cylinders. The plates have recesses milled into their curved undersides into which retractable hooks or fingers, carried on the printing cylinders, may engage in order to hold the plates on the cylinders. The plates themselves are comparatively heavy, and because the printing cylinders of high speed newspaper presses are rotated at high speeds, considerable centrifugal force is exerted by the plates which must be overcome by the hooks engaging the plates. Each hook engages the plate with a force on the order of 300 lbs. in order to overcome this high centrifugal force and each plate usually has four recesses on its underside along both its trailing and leading edges thus necessitating four hooks in the cylinder adjacent each end of the plate to engage these recesses.

In conventional tension lockup cylinders, there are usually four clamping hooks for each plate which are connected onto a rotatable lockup shaft by which the hooks may be rotated into and out of engagement with the recesses on one end of the plate. These hooks are urged separately by springs or the shaft is urged by one spring such that all the hooks engage the side walls of the recesses with the required locking force.

The recesses on the end of the plate opposite the clamping hooks are in conventional lockup apparatus engaged by register hooks which, because the clamping hooks are engaging the plate with a force in one direction, must engage the recesses with an equal and opposite force. The register hooks can usually be moved slightly in order that the plate may be properly aligned on the cylinder. This is particularly useful when the press is used for color printing where extreme accuracy in the positioning of the plate is necessary in order to insure accurate registry of the various colors being printed.

A problem existing heretofore With conventional register hooks is the difficulty of having the hooks accurately engage along their full length with the sides of the recesses. If the hooks are not aligned with the recesses and do not engage the sides of the recesses evenly, the corners of the hooks are likely to dig into the lead plate and contribute to misalignment of the plate on the cylinder. This tendency of the corner of a hook to dig into the plate may be aggravated during a press run to further contribute to misalignment difficulties. The recesses in the plates are often slightly misaligned when the recesses are milled into the plates and sometimes occur because of uneven shrinkage of the hot plate since the plate is cooled after the recesses have been milled.

An attempt has been made heretofore to solve the problem of having the register hooks align with the sides of the recesses by having the hooks mounted in pairs on a register bar and making the bar pivotable about a point, the point being a cam surface contained on a register adjustment bar. While this will reduce some of the difficulties due to misalignment of the register hooks with the recesses, nevertheless it Will not prevent the corners of 3,237,557 Patented Mar. 1, 1966 ICC up apparatus in which each register hook may align itself with the sides of the recesses with which it engages in order to insure that there will be even pressure exerted between the hook and sides of the recess along the complete width of the hook.

A further problem that has existed heretofore with conventional underside tension lockup apparatus is to accurately and swiftly position the plate longitudinally on a cylinder in order to insure accurate side registry of the colors being printed. It is desirable that the cylinder include a means whereby the printing plates may be accurately positioned longitudinally on the cylinder when the plate is initially put on the cylinder and before the plate is locked onto the cylinder. It is, therefore, a further object of our invention to provide an adjustable stop means whereby the plate may be accurately positioned longitudinally on the cylinder as it is being put onto the cylinder.

Broadly, our tension lockup apparatus comprises a printing cylinder having therein a plurality of clamping hooks and register hooks which are adapted to engage recesses on the underside of a printing plate adjacent its trailing and leading edges. The register hooks are mounted in a groove in the printing cylinder such that they may rotate independently of each other about an axis extending in a plane normal to the longitudinal axis of the cylinder and adjustment means are provided for varying the position of the plate on the cylinder. This last named adjustment means may comprise an adjustable stop means in the form of a screw which is threaded in the cylinder and which is movable parallel to the longitudinal axis thereof. The screw has a disc portion protruding beyond the surface of the cylinder to provide a movable stop means to engage with a side of the printing plate such that rotation of the screw will move the protruding portion longitudinally of the cylinder to provide longitudinal positioning of the plate on the cylinder.

Referring to the drawings in which a preferred embodiment of our invention is shown,

FIG. l is a side view of printing cylinder of a printing press;

FIG. 2 is an enlarged broken Isectional View of the cylinder of FIG. l illustrating the longitudinally movable 4stop means by which side register adjustment is effected;

FIG. 3 is a section of FIG. 2 taken along lines 3 3;

FIG. 4 is a partial enlarged section of FIG. 2 taken along lines 4-4;

FIG. 5 is a schematic view illustrating correct and faulty alignment of the register hooks with the sides of recesses contained in printing plates;

FIG. 6 is a partial plan view of the cylinder of FIG. 1 illustrating a portion of the register hooks in section;

FIG. 7 is a sectional view of FIG. 6 taken along lines 7#-7;

FIG. 8 is a sectional view of a portion of FIG. 7 taken along lines 8 8; and

FIG. 9 is an exploded perspective View illustrating placement of register hooks within a register support member.

Referring to FIG. 1 in greater detail, a printing cylinder 1 is shown mounted for rotation in journals 2 carried by press frame members 3. The cylinder shown is of a conventional four plate width and has mounted thereon a plurality of stereotype printing plates 4, 5, 6 and 7 which extend around one-half the periphery of the cylinder. Other printing plates 4', 5', 6' and 7 are positioned diametrically opposite the aforesaid plates so that the cylinder carries a total of eight printing plates. Each plate has four recesses 8 milled or cast on their underside adjacent their leading and trailing edges, the side walls of which are engaged by clamping and register hooks.

A side or longitudinally adjustable stop means denoted generally 10 comprises a screw 11 having a disc or stop portion 12 protruding beyond the surface of the cylinder 1 as shown in FIG. 2. The screw 11 is threaded into the body of the cylinder 1 parallel to the longitudinal axis of the cylinder` so that as the screw 11 is rotated, the disc 12 will move longitudinally with respect to the cylinder. The protruding disc 12 provides a rugged stop against which the plates engage when the plates are mounted on the cylinder prior to lookup. Discs 12 and 12 connected to adjustment means are provided for each of the plates as shown in FIG. l and are positioned near the end of the plates which are engaged by register hooks 14.

A detent or locking means denoted generally 18 is provided to prevent inadvertent rotation of the screw 11 which, in turn, assures that proper side registry will be maintained as the plates are locked up. The detent 18, as shown in FIGS. 2 and 4, comprises a ball 19 which is urged outwardly of a bore 20 in a detent frame member 21 by a spring 22 to engage with grooves 23 cut into a shaft 24 which forms an extension of the screw 11. In addition to providing a locking surface for engagement with the detent, the shaft 24 provides an additional bearing surface for engagement with member 21 so that the screw 11 and disc 12 are held in lirm alignment within the cylinder 1.

The disc V12. is provided around its periphery with a plurality of holes 25 into which a wrench 26 as shown in FIG. 3 may be inserted in order to rotate the disc and screw whereby the longitudinal adjustment on the plates may be made in order to control side registry.

The adjustment means shown presents a sturdy co-nstruction which will withstand the abuses of having the heavy plates thrown on the cylinder and banged against the protruding disc. As illustrated in FIG. 2, the only portion of the adjustment means protruding from the cylinder is the disc and all other parts of the adjustment means, such as the screw and locking detent, are within the body of the cylinder and therefore are not subjected to the banging of the plates.

FIG. 5 illustrates the localized concentration of forces when the recesses 8 contained in a plate are slightly misaligned with respect to the register hooks. The left-hand portion of FIG. 5 shows the concentration of forces exerted by register hooks 14 against a side 30 of a recess e contained on the underside of a plate where the hooks are not rotatable with respect to each other. As shown in FIG. 5, the forces act at one point which in actual practice would cause one corner of the hook 14 to dig into the side wall of the relatively soft, lead plate. This digging in of the hook would tend to prevent any adjustment of the plate on the cylinder since it would prevent any sideways movement of the plate on the cylinder. Further, there would be a tendency for the hook to dig further into the side wall 30 during a press run which, if no other compensating means were provided, could result in a reduction of the lockup pressure on the plate and so increase possibility of movement of the plate on the cylinder.

The right-handy portion of FIG. 5 illustrates the even application of forces by a hook on the side wall of the recess where the book is allowed to rotate about an axis contained in a plane extending normal to the longitudinal axis of the cylinder. This even application of force along the complete length of the hook diminishes any tendency of the hook or any portion thereof to dig into the side wall of the recess,

The clamping hooks and register hooks incorporating the structure by which the register hooks are made rotatable with respect to each other is illustrated in FIGS. 6-9 where the register hook 14 is shown engaged with one end of the plate 4'. The other end of the plate is engaged by la clamping hook similar to clamping hook 33 shown engaging one end of the plate 4.

The clamping or lockup mechanism for the clamping hook 33 comprises an -actuator arm 34 and Belleville springs 35, all held together by means of a bolt 36 and nut 37. The actuator arm 34 has a bearing face 38 on one end adapted to Contact the member 33. The other end of member 34 has a rounded portion 39 which bears in a groove 40 contained on the hook member 33. Arm 34 is mounted on the hook member 33 with the springs 35 interposed between a washer 41 and the bottom of a recess 42 contained within the hook member. The bolt 36 extends through the arm so that when nut 37 is screwed down, the face 38 is forced into contact with the member 33 in order to prelo-ad or prestress the springs. The members 33, 34 and 35 thus form a self-contained clamping unit which is inserta'ble into the groove 43 contained in the printing cylinder. The member 30, in addition, has thereon lugs which are adapted to be rotatably received in clamp supports not shown in order that the hook 33 may be pivoted into and out of clamping engagement with the plate.

A rotatable lock-up shaft 46' extends longitudinally in the groove 43 and passes through a support member 47. Rotation of the shaft in fa coun-terclockwise direction as shown in FIG. 7 will first bring a cam surface 48 into contact with arm 34 causing the member 33 to rotate 'about lugs 45 until it engages a recess. Further rotation of shaft 46 will then move the arm 34 so that the face 38 is lifted olf of member 33 further compressing the preloaded springs 35 whereby the linger 33 will securely lock the plate to the cylinder.

The register hook 14 which engages the ends of the plate opposite from the clamping hook comprises a shank portion 50 which h'as protruding lips 511 for a purpose to be explained later. The hook member 14 is carried by a hook support member 52 which, in turn, is slidable in a circumferential direction in a longitudinally extending groove 54 contained within the member 47. The support member 52 has a cam base 53 which bears against fthe incline surface 55 off a longitudinally movable register adjustment bar 55'. Movement of the register bar 5S longitudinally will cause the register support member 52 and hooks 14 to move i-n a circumferential direction so as to provide Iaccurate circumferential adjustment of registry of `the plate on the cylinder.

Each support member 5.2 carries two hook members 14 and has bores 57 drilled therein with additional drilled out portions 58 through which the lips S1 and shank 50 may be inserted as shofwn in FIG. 9. The underside of the support member 52, in addition, has a cutout 59 which is the same diameter as the lip 51 and which extends partly up i-nto the support member so as to present a lower surface against which the upper surface of lips 51 may bear. The hooks 14 .are inserted into ythe support member by initially `turning the hook member 90 with lrespect to t-he support member so that the :lips 51 may be inserted through the cutouts 58. The hook members 14 are then turned 90 so that the lips 51 engage cutouts 59.

'Ilwo springs 60 are provided @for each hook member 14 yand are mounted in holes 61 drilled into the support 47. A plug 612 is urged against `the hook member by each spring and the springs associated with each hook are positioned adjacent the sides of the hooks on oppo site sides of the axis of the bores 57. This construction insurers that the hooks 14 remain in parallel alignment with each other prior to the plate being locked to the printing cylinder by the clamping or locking hooks 33. In addition, the springs 60 further insure that the cam 5 suraces 53 and 55 maintain engagement runder all operating conditions.

-It is seen that the particular register adjustment means described provides register hooks which may be e-asily assembled into a printing cylinder and which will insure even loading 'between the hook and side wall of the recess thus reducing any cutting or digging in of the hook into the plate because of any misalignment of the recesses in the plate.

While we have shown land described a particular construction of the clamping or lookup hooks, it is to be understood that other clamping constnuctions can be used and that the one shown was for Iputnposes of example only.

We claim:

1. An underside tension lookup apparatus for locking a printing plate having recesses on the underside thereof onto a printing cylinder, comprising `a plurality of clamping hooks carried by said cylinder for engaging the recesses on one end of said plate, means for pivoting said clamping hooks into and out of clamping engagement with their recesses, register hooks for engaging recesses on the opposite ends of said plate from said clamping hooks, a register hook support member carried by said cylinder for supporting two said register hooks with each said register hook being rotatably mounted in said sa-id support member whereby when said clamping hooks are pivoted in clamping engagement with their recesses, said register hooks are free to rotate to align themyselves with the sides ot their recesses, two springs operatively -positioned between said cylinder and opposite sides of each register hook to align said hooks substantially longitudinally of said cylinder when said hooks are out of engagement With the recesses, and means for moving said hook support member along a chord in- 6 serted within the circumference of the cylinder in order to vary circumferential registry of a plate.

2. An underside `tension lookup apparatus for locking la printing plate having recesses on the underside thereof tonto a printing cylinder, comprising a plurality of clamping hooks carried by said cylinder for engaging the recesses on one end of said plate, means for pivoting said clamping hooks into and out of clamping engagement with their recesses, register hooks for engaging recesses on the opposite end of said plate from said clamping hooks, la register hook support member carried by said cylinder for supporting two said register hooks with each said negister hook being rotatably mounted in said support member whereby when said clamping hooks are pivoted in clamping engagement with their recesses, said regi-ster hoo-ks -are free to rotate to align themselves with the sides of their recesses, spring means operatively positioned between said cylinder and in engagement with the opposite sides of each said register hook to align said hooks substantially longitudinally off said cylinder when said hoolos are out of engagement with the recesses, and means for moving said hook support member along a chord inserted within the circumference of the cylinder in order to vary circumferential registry of a plate.

References Cited by the Examiner UNITED STATES PATENTS 1,730,122 10/1929 Busk lOl- 415.1 2,681,007 6/19'54 Hi'arless 101--37 8 2,818,806 1/1958 Harless 101-378 2,900,903 8/1959 Chase 101--378 2,965,024 12/ 1960 Ziebell 101-37 8 ROBERT E. PULFR-EY, Primary Examiner.

EUGENE R. CAPOZIO, Examiner. 

1. AN UNDERSIDE TENSION LOCKUP APPARATUS FOR LOCKING A PRINTING PLATE HAVING RECESS ON THE UNDERSIDE THEREOF ONTO A PRINTING CYLINDER, COMPRISING A PLURALITY OF CLAMPING HOOKS CARRIED BY SAID CYLINDER FOR ENGAGING THE RECESSES ON ONE END OF SAID PLATE, MEANS FOR PIVOTING SAID CLAMPING HOOKS INTO AND OUT OF CLAMPING ENGAGEMENT WITH THEIR RECESSES, REGISTER HOOKS FOR ENGAGING RECESSES ON THE OPPOSITE END OF SAID PLATE FROM SAID CLAMPING HOOKS, A REGISTER HOOK SUPPORT MEMBER CARRIED BY SAID CYLINDER FOR SUPPORTING TWO SAID REGISTER HOOKS WITH EACH SAID REGISTER HOOK BEING ROTATABLY MOUNTED IN SAID SUPPORT MEMBER WHEREBY WHEN SAID CLAMPING HOOKS ARE PIVOTED IN CLAMPING ENGAGEMENT WITH THEIR RECESSES SAID REGISTER HOOKS ARE FREE TO ROTATE TO ALIGN THEMSELVES WITH THE SIDES OF THEIR RECESSES, TWO SPRINGS OPERATIVELY POSITIONED BETWEEN SAID CYLINDER AND OPPOSITE SIDES OF EACH REGISTER HOOK TO ALIGN SAID HOOKS SUBSTANTIALLY LONGITUDINALLY OF SAID CYLINDER WHEN SAID HOOKS ARE OUT OF ENGAGEMENT WITH THE RECESSES, AND MEANS FOR MOVING SAID HOOK SUPPORT MEMBER ALONG CHORD INTO VARY CIRCUMFERENTIAL REGISTRY OF A PLATE. 